THURSDAY, March 13, 2014 (HealthDay News) -- Poisonings, mostly from drug overdoses, are the leading cause of accidental death among working-age adults in the United States, a new report shows.

In half of those cases, the overdose resulted from prescription-drug abuse, according to the U.S. National Safety Council. The council has been putting out an annual report on safety statistics and trends across the United States since 1921.

For younger people, motor vehicle crashes caused the most injury deaths, with distractions caused by cellphones contributing significantly to those crashes.

Meanwhile, falls caused the most fatal injuries among people older than 65.

Overall, injury deaths increased 3.2 percent in 2012 from the year before, driven by increases in accidental deaths at home and in cars, according to the report.

Poisoning used to be a concern only for young children "getting in the medicine cabinet and under the kitchen sink," said Ken Kolosh, statistics manager for the National Safety Council.

But starting in 1993, Kolosh said, a trend began to emerge of people in their 30s and 40s dying of unintentional poisoning, largely due to drug abuse.

That trend has only strengthened, with poisoning now the major cause of unintentional fatal injuries among working-age adults aged 25 to 64. In 18 states and Washington, D.C., poisoning is the leading cause of accidental death.

Drugs both legal and illicit accounted for nearly 91 percent of poisoning deaths reported in 2010, the report found, with alcohol poisoning accounting for an additional 6 percent.

About half of those poisoning deaths are caused by overdoses of prescription drugs, Kolosh said.

"Heroin death also appears to be increasing, and we will be tracking that as well," he added.

Young people, meanwhile, are dying in crashes that appear to be related to cellphones and other distractions -- not alcohol or drugs, the report found.

About 7,800 people aged 5 to 24 died in traffic accidents in 2010, according to the report.

Driver error accounts for 95 percent of auto crashes among 15- to 18-year-old drivers, according to data the report cited from the National Highway Traffic Safety Administration.

Distracted driving accounted for about 46 percent of those errors, followed by bad decisions such as following too closely or driving too fast, which accounted for 40 percent.

"These issues are more related to driver inexperience" than driving drunk or drugged, Kolosh said.

Why are kids driving distracted? The researchers said cellphone use is now estimated to be involved in 26 percent of all motor vehicle crashes.

About 5 percent of those crashes involve texting, and another 21 percent involve drivers talking on handheld or hands-free cellphones.

Unfortunately, crashes caused by young drivers affect everyone. "Young drivers count for less than half the overall life toll in fatal crashes," Kolosh said.

Nearly 1,900 young drivers died in the crashes they caused in 2012, the report found. Those accidents also killed nearly 1,100 people riding in the same car, more than 1,200 people in other cars and about 500 who were not in a car.

Other findings from the report include:

The number of falls among the elderly has risen 112 percent since 1999. More than 21,600 seniors died from injuries caused by a fall in 2010.

Unintentional injury deaths cost more than $190 billion annually.

The United States leads all other countries in the number of reported cases of occupational injury deaths, with more than 4,500 in 2010.

Motor vehicle deaths in 2012 were at their lowest level in February and at their highest level in July.

The four-day period around Thanksgiving was the holiday period with the highest percentage of alcohol-impaired driving deaths.